Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly, idempotent, closed-world behavior, so the safety profile is covered. The description adds provenance ('PartsTable read model') and signals that NSN/FSC fields may be absent ('when present'), which is genuine extra context, but it omits what happens when the part is not found — a key behavior for a lookup tool.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

A single dense sentence with no filler: the verb and resource come first, followed by the returned field set and the data source. Every clause adds information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description correctly compensates by enumerating the returned fields, giving the agent a clear picture of the response shape. The only gap is not-found/error behavior, which is minor for a simple single-parameter read.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% with a single well-documented 'partNumber' parameter, so the schema carries parameter meaning. The description adds nothing beyond it regarding format, exactness, or normalization expectations (e.g., whether normalized PNs are accepted), so baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb ('Get') and resource ('the part record') and enumerates the returned facets: identity, manufacturer, description, category, lifecycle, and NSN/FSC classification. This clearly separates it from sibling writes/validators, though it never explicitly differentiates from search-parts or get-substitutes.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The tool is framed as a direct record lookup, which implicitly signals exact-part-number retrieval rather than exploratory search. However, no alternatives are named and there is no guidance on when to use search-parts or normalize-pn first, so the agent must infer the selection logic.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.